Getting your Trinity Audio player ready...

By Jim Tankersley

Update, 10:30 a.m. — The latest Los Angeles Times / Bloomberg poll supports the Edwards-aggressive strategy in the “21” game (see below). The poll shows the former North Carolina senator moving 10 percentage points closer to Obama since June — a five-point gain for Edwards added to a five-point slide for Obama. The two candidates both trail Clinton, who has nearly half the support in the national poll. But now Edwards is statistically tied — which is to say, within the poll’s margin of error — with Obama.

John Edwards and Barack Obama both love to hoop, so it seems fitting to explain their current presidential-primary conundrum through a basketball metaphor.

When only three players show for a pick-up game – not enough for even some half-court two-on-two – they often pass the time with a game called “21”. The rules are simple: One player has the ball and tries to score. The other two play defense. When someone scores, they shoot free throws and, if they make three in a row, get the ball back to try to score another basket. First to 21 points wins.

The strategy comes when you don’t have the ball. Do you aggressively guard the player trying to score, in hopes of forcing a bad shot? Or do you hang out around the basket, hoping the other defender will guard the player on offense, and position yourself to rebound a missed shot?

Play aggressively and you risk missing the rebound – but play back and you risk letting the offensive player score (in the event that the other defender does a poor job or, worst of all, hangs back for the rebound, too).

Right now, the Democratic nomination fight is a big game of 21. Hillary Clinton has the ball. Edwards is pressuring her aggressively. And Obama, for the most part, has looked content to wait for the rebound.Consider the recent attacks on Clinton’s vote to designate the Iranian Revolutionary Guard a “terrorist organization.” Edwards was the first to criticize the vote, in a Sept. 26 debate in New Hampshire, as a first step toward possible war with Iran. He continued to pound the New York senator over the vote for the next month. Only later did Obama – who missed the Senate vote in question – jump in with criticism of his own.

Edwards was also the first to slam Clinton over taking presidential campaign checks from lobbyists (he and Obama do not) and for her sincerity, following a New York Times article that suggested her Iran vote was a move from “primary mode” to “general election” mode.

“Instead of moving from primary mode to general election mode, why don’t we have tell-the-truth mode, all the time, and not say something different one time than we say another time?” Edwards said earlier this month. Obama’s Clinton criticisms have grown sharper lately, but not as sharp as that.

Obama and Edwards will face tough choices soon. It’s clear they haven’t stopped Clinton from scoring so far; recent polls show her padding her lead nationally and in key early states. Either Edwards or Obama – and maybe both – will likely need to crank up the defensive pressure to have any hope of denying her a slam-dunk nomination. That probably means negative television ads.

Problem is, the guy best positioned to reap the benefits of an attack-ad campaign is the one who stays out of it. In multiple-candidate races, voters often punish both the perpetrators and the victims of mudslinging.

In 21, two players can run each other all over the court, tire, and watch the third pluck a rebound, score at will, and win in the end. Of course, sometimes the aggressive defender steals the ball and pulls off the upset.

This is the Obama-Edwards conundrum as Iowa and New Hampshire approach. Who goes for the steal? Who plays for the rebound?

And, perhaps most daunting for both their campaigns, what happens if Clinton keeps sinking jumpers, no matter who guards her?